testing locks

pool-server.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"log"
 	"net/http"
 	"strconv"
 
@@ -22,6 +23,7 @@ func NewPoolServer(pool GrainPool, pod_name string) *PoolServer {
 
 func (s *PoolServer) HandleGet(w http.ResponseWriter, r *http.Request) error {
 	id := r.PathValue("id")
+	log.Printf("Getting cart %s\n", id)
 	data, err := s.pool.Get(ToCartId(id))
 	if err != nil {
 		return err

synced-pool.go

@@ -319,11 +319,23 @@ func (p *SyncedPool) Negotiate() {
 
 }
 
+func (p *SyncedPool) GetHealthyRemotes() []*RemoteHost {
+	p.mu.RLock()
+	defer p.mu.RUnlock()
+	remotes := make([]*RemoteHost, 0, len(p.remotes))
+	for _, r := range p.remotes {
+		if r.IsHealthy() {
+			remotes = append(remotes, r)
+		}
+	}
+	return remotes
+}
+
 func (p *SyncedPool) RequestOwnership(id CartId) error {
 	ok := 0
 	all := 0
-	p.mu.RLock()
-	for _, r := range p.remotes {
+
+	for _, r := range p.GetHealthyRemotes() {
 		if !r.IsHealthy() {
 			continue
 		}
@@ -342,7 +354,7 @@ func (p *SyncedPool) RequestOwnership(id CartId) error {
 		}
 		ok++
 	}
-	p.mu.RUnlock()
+
 	if ok == 0 && all > 0 {
 		p.removeLocalGrain(id)
 		return fmt.Errorf("no remotes confirmed change")
@@ -361,8 +373,7 @@ func (p *SyncedPool) removeLocalGrain(id CartId) {
 }
 
 func (p *SyncedPool) AddRemote(host string) error {
-	p.mu.Lock()
-	defer p.mu.Unlock()
+
 	_, hasHost := p.remotes[host]
 	if host == "" || p.IsKnown(host) || hasHost {
 		return nil
@@ -378,7 +389,9 @@ func (p *SyncedPool) AddRemote(host string) error {
 		MissedPings: 0,
 		Host:        host,
 	}
+	p.mu.Lock()
 	p.remotes[host] = &remote
+	p.mu.Unlock()
 	go func() {
 		<-remote.PersistentConnection.Died
 		log.Printf("Removing host, remote died %s", host)